CHR 



<JHR 



in the arbitrary supposition and conjec- 

 tures of his enemies. 



" That there once existed such a person 

 as Jesus Christ; that he appeared in Judea 

 In the reign of Tiberius; that he taught a 

 system of moralssuperior to any inculcat- 

 ed in the Jewish schools; that he was 

 crucified at Jerusalem ; and that Pontius 

 Pilate was the Roman governor by whose 

 sentence he was condemned and execut- 

 ed; are facts which no one can reasonably 

 call in question. The most inveterate 

 Deists admit them without difficulty: and, 

 indeed, to dispute these facts would be 

 giving the lie to all history. As well might 

 we deny the existence of Cicero, as that 

 of a person by the name of Jesus Christ. 

 And with equal propriety might we call 

 in question the orations of the former, as 

 the discourses of the latter. We are mo- 

 rally certain that the one entertained the 

 Romans with his eloquence, and that the 

 other enlightened the Jews with his wis- 

 dom. But it is unnecessary to labour these 

 points,because they are generally conced- 

 ed. They who affect to despise the evan- 

 gelists and Apostles profess to reverence 

 Tacitus, Suetonius, and Pliny. And these 

 eminent Romans bear testimony to seve- 

 ral particulars which relate to the person 

 of Jesus Christ, his influence as the foun- 

 der of a sect, and his crucifixion. From a 

 deference to human authority, all there- 

 fore acknowledge that the Christian reli- 

 gion derived its name from Jesus Christ. 

 And many among the Deists are so just to 

 its merits, as to admit that he taught bet- 

 ter than Confucius, and practised better 

 than Socrates or Plato. 



** To come then to the question : Why 

 are you a Christian ? 1 answer, Because 

 the Christian religion carries with it inter- 

 nal marks of its truth ; because not only 

 without the aid, but in opposition to the 

 civil authority, in opposition to the wit, 

 the argument, and violence of its enemies, 

 it made its way, and gained an establish- 

 ment in the world; because it exhibits the 

 accomplishment of some prophecies, and 

 presents others which have been since 

 fulfilled; and because its author displayed 

 an example, and performed works, which 

 bespeak not merely a superior, but a di- 

 vine character. Upon these several facts I 

 ground my belief as a Christian. And, till 

 the evidence on which they rest can be 

 invalidated by counter evidence, I must 

 retain my principles and my profession.'* 



CHROMATICS, is that part of optics 

 wh'ch explains the several properties of 

 the colours of light and of natural bodies. 



Before the time of S ir Isaac Newton, the 



notions concerning colour were very 

 vague. Des Cartes accounted colour a 

 modification of light; and he imagined 

 that the difference of colour proceeds 

 from the prevalence of the direct or rota- 

 tory moti< n of the particles of light. Gri- 

 inaldi, Dechales, and many others, ima- 

 gined that the differences of colour de- 

 pended upon the quick or slow vibrations 

 of a certain elastic medium, with which 

 the universe is filled. Rohault conceived 

 that the different colours were made by 

 the rays of light entering the eye at dif- 

 ferent angles with respect to the optic 

 axis. And Dr. Hooke imagined that co- 

 lour is caused by the sensation of the ob- 

 lique or uneven pulse of light; which be- 

 ing capable of no more than two varieties, 

 he concluded there could be no more 

 than two primary colours. 



Sir Isaac Newton, in the year 1666, be- 

 gan to investigate this subject; when find- 

 ing that the coloured image of the sun, 

 formed by a glass prism, was of an oblong 

 and not of a circular form, as, according 

 to the laws of equal refraction, it ought 

 to be, he conjectured that light is notho- 

 mogeneal : but that it consists of rays of 

 different colours,and endued with divers 

 degrees of refrangibility. And, from a 

 farther prosecution of his experiments, lie 

 concluded that the different colours of bo- 

 dies arise from their reflectingthis or that 

 kind of rays most copiously. This method 

 of accounting for the different colours of 

 bodies soon became generally adopted, 

 and still continues to be the most prevail- 

 ing opinion. It is hence agreed that the 

 light of the sun, which to us seems white 

 and perfectly homogeneal, is composed of 

 no fewer than seven different colours,, 

 viz. red, orange, yello\v, green, blue, 

 purple, and violet or indigo : that a body 

 which appears of a red colour has the 

 property of reflecting the red rays more 

 plentifully than the rest ; and so of the 

 other colours, the orange, yellow, green. 

 Sec.: also that a body which appears black, 

 instead of reflecting, absorbs all or the 

 most part of the rays that fall upon it; 

 while, on the contrary, a body which ap- 

 pears white reflects the greater part of all 

 the rays indiscriminately, without sepa- 

 rating them one from another. 



The foundation of a rational theory of 

 colours being thus laid, the next inquiry 

 was, by what peculiar mechanism, in the 

 structure of each particular body, it was 

 fitted to reflect one kind of rays more 

 than another, and this is attributed by 

 Sir I. Newton to the density of these bo- 

 dies. Dr. Hooke remarked, that thin 



